Simon is a very tall 3-year-old. He measures at 4 feet and at a certain time of day casts a shadow of 2.5 feet. In his yard is a huge oak tree. At the same time of day, the tree casts a shadow of 28 feet. How tall is the oak tree? Note: Figure is not drawn to scale. 4 ft. 2.5 ft. 28 ft.